EP2448369A1 - Electrical connection device for an electric heating element of a hot runner nozzle - Google Patents

Abstract

The electrical connection device (10) has a connection line (30) and contact elements (32,33) which are electrically contacted to a heating element (20). The ends of connection contacts (22,23) of the heating element are provided with insulating component (50). The connection contacts are electrically separated from one another such that the insulating component is partially arranged in a receiving sleeve and the cable of connecting line is fixable to the contact elements.

Description

The invention relates to an electrical connection device for an electrical heating element of a hot runner nozzle according to the preamble of claim 1 and to a hot runner nozzle according to claim 17.

Hot runner nozzles are used in injection molds in order to supply a flowable mass - for example a plastic melt - at a predeterminable temperature under high pressure to a separable mold insert. They usually have a material tube with a flow channel that ends in a nozzle orifice. The latter forms a nozzle outlet opening at the end, which opens via a gate in the mold insert (mold cavity).

So that the flowable mass does not cool prematurely within the flow channel, an electrical heating element is provided on the outside of the material tube. This has a sleeve-shaped carrier element and an electrical conductor which generates heat when an electrical voltage or when flowing through an electric current.

The electrical conductor can - as in DE 10 2006 049 669 A1 disclosed - be a heating coil formed of resistance wire. DE 10 2006 049 667 A1 on the other hand, so-called thick-film heating elements, which are applied by means of the screen-printing process as heating conductor tracks on the carrier element, are used as electrical conductors. Between the support member and the electrical conductor, an insulating layer is usually provided, which is also applied by screen printing as a thick film. In order to further reduce the size of the heating element or the hot runner nozzle, you can the insulating layer and the Heizleiterbahnen - as in DE 199 41 038 A1 described - also apply directly to the outer wall of the material tube.

The following is an example of a thick-film heating on a cylindrical support member. However, the invention is not limited thereto, but equally applicable to other heating elements.

• ■ sie muss lösbar ausgebildet sein, um die Heißkanaldüse im Spritzgießwerkzeug ein- und ausbauen zu können und/oder um ein Heizelement im Falle eines Defekts austauschen zu können;
• ■ sie muss einen stets ausreichenden und zuverlässigen elektrischen Kontakt zwischen den Anschlusskontakten der Heizleiterbahnen und der mit der Stromquelle verbundenen Anschlussleitung herstellen;
• ■ sie muss aufgrund der beim Spritzgießen vorherrschenden hohen Temperaturen temperaturbeständig sein und mechanischen Zugbelastungen standhalten, die beim Ein- und Ausbau der Heißkanaldüse und/oder beim Auswechseln des Heizelements auftreten können.

In order to supply the thick-film heating with energy, a connection contact is provided at the ends of the heating conductor in each case, for example in the form of a pigtail or a connecting pin (see WO 2005/053361 A1 . DE 10 2008 004 526 A1 or DE 10 2008 015 376 A1 ). About the terminal contact the Heizleiterbahn is connected to the connecting lead of a power source, such an electrical connection must always meet the following requirements:

• ■ It must be designed to be detachable, in order to install and remove the hot runner nozzle in the injection mold and / or to replace a heating element in the event of a defect can;
• ■ it must always provide sufficient and reliable electrical contact between the contacts of the heating conductors and the connecting cable connected to the power source;
• ■ It has to be temperature resistant due to the high temperatures prevailing in injection molding and can withstand mechanical tensile loads that occur during injection molding Installation and removal of the hot runner nozzle and / or can occur when replacing the heating element.

US 4,486,650 B1 discloses a releasable plug connection between the terminal ends of a heating coil and the connecting lead of a power supply. The ends of the heating coil are provided with radially outwardly directed contact pins, which are arranged approximately centrally in a respective sleeve. The ends of the connecting cable are provided with sleeve-shaped plug contacts, which are each housed in a plug housing. The latter are inserted into the sleeves, wherein the electrically conductive connection between the outer surface of the contact pins and the inner surface of the plug contacts is made. In order to prevent the plug housing from coming off the sleeve, a clamping device in the form of a union nut is provided, which is screwed onto an external thread of the sleeve. For each connection a separate plug contact is necessary.

WO 2004043672 discloses a heating element for placement on a pipe or a hot runner nozzle, wherein the heating element is provided with a current-carrying conductor, which is connectable via connecting lines to a power source. The connection lines each have an end-side contact piece, which can be brought into contact with a contact surface of the heating element. Further, a clamping device is provided, by means of which the contact piece is clamped against the heating element, wherein the contact piece rests loosely on the contact surface of the heating element and wherein the clamping force of the clamping device acts substantially normal to the contact surface and thereby biases the contact piece against the contact surface. By loosening the clamping device, the contact piece is released from the contact surface, whereby the heating element can be removed and replaced. The clamping force generated by the clamping device is generated either by a spring or by a clamping screw.

Such a solution has the disadvantage that the electrical contact between the contact surfaces of the heating element and the contact pieces of the connecting line depends both on the nature and the cleanliness of the surfaces to be contacted and on the clamping force of the clamping device. If the contact surfaces are uneven or dirty, or if the spring force decreases, contact problems may occur. This usually leads to power losses within the heating element. Further In the area of the connection contacts, excessive heat generation occurs, which can lead to damage to the heating element.

The aim of the invention is to overcome these and other disadvantages of the prior art and to provide an improved electrical connection device for an electrical heating element of a hot runner nozzle, which at least partially meets the above requirements. The connection device should also be constructed inexpensively by simple means and be easy to handle. The aim is in particular a simple and quick installation.

Main features of the invention are specified in the characterizing part of claim 1 and in claim 17. Embodiments are the subject of claims 2 to 16.

In a connection device for producing an electrical connection between an electrical heating element of a hot runner nozzle and a connecting line which is connected to a current source, wherein the connecting line has contact elements which are electrically contactable with connection contacts of the heating element, the invention provides that the connection contacts of the heating element in an insulating body, which electrically disconnects the terminal contacts and that the insulating body is at least partially disposed in a receiving sleeve, wherein the connecting line is fixed in or on the receiving sleeve, that the contact elements of the connecting line electrically contact the terminal contacts of the heating element.

The receiving sleeve forms together with the insulating body a connection point, in particular a kind of socket for receiving the connecting cable and their contact elements, which are always safely and reliably brought into contact with the connection contacts of the heating element within the receiving sleeve, so that for the operation of the hot runner nozzle is always sufficient and permanent electrical contact between the terminals of the Heizleiterbahnen and connected to the power supply line is guaranteed. The latter can also be set releasably on the heating element via the receiving sleeve, so that the hot runner nozzle can be installed and removed quickly and conveniently in the injection mold. Furthermore, the heating element can be replaced quickly in the event of a defect, which has a very favorable effect on the maintenance and installation costs. In addition, the invention holds Connection device easily stood even higher temperatures, and it provides a mechanical strain relief for the connection contacts of the heating element, which is important when installing and removing the hot runner nozzle and / or when replacing the heating element.

In order to further improve the electrical contact between the connection contacts of the heating element and the contact elements of the connecting line, a development of the invention provides that the connection contacts of the heating element are provided at the end with contact pins. These lead the most sensitive and soldered to the ends of Heizleiterbahnen connection contacts of the heating element and offer in conjunction with the Isolierköper a significantly improved mechanical stability.

The insulating body preferably has a neck portion and a base portion, wherein the neck portion is preferably in the receiving sleeve, while this is supported on the base portion of the insulating body. The insulating body thus not only electrically separates the terminal contacts of the heating conductor tracks and the contact pins. It also contributes significantly to the stability of the connection device, which easily withstands mechanical and thermal stresses.

This also contributes, if according to a further embodiment of the invention, the base portion of the insulating body covers the terminal contacts of the heating element. These are reliably protected against external environmental influences. At the same time, the base has a relatively large support surface, which has a favorable effect on the stability and reliability of both the connection device and the hot runner nozzle.

Another important embodiment of the invention provides that a further contact pin is provided in the insulating body, which is preferably longer than the other pins. As a result, this further contact pin first comes into contact with a correspondingly assigned contact elements of the connecting line when joining the connection contacts in the receiving socket. This is particularly advantageous if the further contact pin forms a ground connection for the heating element. Thus, a ground connection is always made when connecting the heating element to the power supply before the actual power contacts receive electrical contact. Short circuits or uncontrolled discharges are thereby effectively avoided.

The further contact pin can be connected, for example, via a cable to the substrate or the carrier element of the heating element. For this purpose, a recess is provided in the insulating body, through which the ground cable from the insulating body can be led out to the outside.

The contact pins and the further contact pin are non-positively and / or positively fixed in the insulating body, which has an extremely favorable effect on the stability of the connection device. In this case, the contact pins can protrude either over the neck portion of the insulator or they are at least partially sunk in the insulator.

Advantageously, between the Isolierköper and the receiving sleeve an anti-rotation, so that both components are always reliably positioned during assembly and during operation.

An equally important embodiment of the connection device according to the invention provides that the connection line end has a plug which is releasably fixed in the receiving sleeve. As a result, the connecting line can always be set quickly and easily on the heating element and just as easily and conveniently removed. The assembly work for the hot runner nozzle and the heating element is reduced to a minimum. It is expedient if the plug is non-positively and / or positively fixed in the receiving sleeve, in particular when the plug is latched to the receiving sleeve. For this purpose, the receiving sleeve is provided with a locking groove for the plug. This has corresponding latching elements which engage with the locking groove during insertion of the plug into the receiving sleeve.

So that the preferred three or multi-pin connector is always polarized correctly when inserted into the receiving sleeve and can not be twisted, a guide groove for the plug is formed in the receiving sleeve. The latter is provided on its outer circumference with a projection corresponding to the guide groove in the receiving sleeve. Guide groove and projection thus forms a kind of key, which ensures that the terminal contacts of the heating element and the ground terminal are always correctly assigned and poled. Connection errors are effectively avoided.

According to a further embodiment of the invention, a spring element is arranged between the receiving sleeve and the insulating body. This is supported in the axial direction the receiving sleeve preferably on the base of the insulating body, so that it is pressed in the mounted position with a permanent and defined force against the heating element. The spring element may be formed integrally with the receiving sleeve. But you can also use a separate spring element, such as a plate spring or a leaf spring.

Another important embodiment of the connection device according to the invention provides that the receiving sleeve carries a tab at its lower end. This serves as a rotation of the receiving sleeve relative to a housing of the hot runner nozzle. Since the housing for mounting the nozzle is usually provided with a slot or a recess, the tab can also be designed such that this slot or the recess is closed by the tab, so that the heating element completely from the housing and the tab enclosed and thus protected. The tab can be formed integrally with the receiving sleeve. But you can also train these separately from the receiving sleeve.

Another function of the tab may be to form a guide or implementation for a connecting lead of a temperature sensor. For this purpose, the tab is provided with a recess which receives the connecting cable of the temperature sensor.

An important embodiment further provides that the receiving sleeve is arranged concentrically in an outer sleeve, wherein the receiving sleeve is axially fixed-rotatably mounted in the outer sleeve. For this purpose, the outer sleeve is provided at its upper end with an inner peripheral groove, while the receiving sleeve is provided at its upper end with a radially outwardly directed flange, which engages positively in the assembled position of the sleeves from the inside into the circumferential groove of the outer sleeve. For mounting both components, the receiving sleeve is provided with slots in the axial direction, so that the wall segments or sections remaining therebetween when fitting the outer sleeve on the receiving sleeve elastically dodge inward and then again can spring radially outward. Outer sleeve and receiving sleeve are thus locked into each other, so that an axially fixed-rotatable connection is formed.

The outer sleeve serves to set the receiving sleeve and the Isolierköper on the heating element, in particular on the hot runner nozzle, wherein the outer sleeve with its lower end to a housing of Hei βkanaldüse can be fixed, in particular by means of a screw connection. For this purpose, the outer sleeve is provided at its lower end with a thread which is screwed into a corresponding thread in the housing or.

A hot runner nozzle for an injection mold is expediently provided with a connection device according to the invention.

Fig. 1

eine Seitenansicht einer Heißkanaldüse mit einer Anschlusseinrichtung für ein Heizelement, teilweise im Schnitt;

Fig. 2

die Anschlusseinrichtung von Fig. 1 in einer vergrößerten Darstellung;

Fig. 3

eine Draufsicht auf die Anschlusseinrichtung von Fig. 1;

Fig. 4

eine Seitenansicht eines Isolierkörpers mit einem eingesetzten Kontaktstift;

Fig. 5

eine Schnittansicht des Isolierkörpers von Fig. 4 ohne Kontaktstifte;

Fig. 6

eine Draufsicht auf den Isolierkörper von Fig. 5;

Fig. 7

eine Druntersicht des Isolierkörpers von Fig. 5;

Fig. 8

eine Rückansicht des Isolierkörpers von Fig. 5;

Fig. 9

eine Seitenansicht einer Verdrehsicherung;

Fig. 10

eine Schnittansicht der Verdrehsicherung von Fig. 9;

Fig. 11

eine Draufsicht auf die Verdrehsicherung von Fig. 9;

Fig. 12

eine Druntersicht der Verdrehsicherung von Fig. 9;

Fig. 13

eine Seitenansicht einer Sicherungshülse;

Fig. 14

eine Schnittansicht der Sicherungshülse von Fig. 13;

Fig. 15

eine andere Ausführungsform einer Verdrehsicherung.

Further features, details and advantages of the invention will become apparent from the wording of the claims and from the following description of exemplary embodiments with reference to the drawings. Show it:

Fig. 1

a side view of a hot runner nozzle with a connection device for a heating element, partially in section;

Fig. 2

the connection device of Fig. 1 in an enlarged view;

Fig. 3

a plan view of the connection device of Fig. 1 ;

Fig. 4

a side view of an insulating body with an inserted contact pin;

Fig. 5

a sectional view of the insulating body of Fig. 4 without contact pins;

Fig. 6

a plan view of the insulator of Fig. 5 ;

Fig. 7

a bottom view of the insulator of Fig. 5 ;

Fig. 8

a rear view of the insulator of Fig. 5 ;

Fig. 9

a side view of a rotation;

Fig. 10

a sectional view of the rotation of Fig. 9 ;

Fig. 11

a plan view of the rotation of Fig. 9 ;

Fig. 12

a Druntersicht the rotation of Fig. 9 ;

Fig. 13

a side view of a locking sleeve;

Fig. 14

a sectional view of the locking sleeve of Fig. 13 ;

Fig. 15

another embodiment of a rotation.

In the Fig. 1 generally designated 1 hot runner nozzle is used in a (not shown) injection molding tool to a flowable plastic melt a supply separable mold insert. It has a material pipe 2 with a melt channel (not shown) which ends in a nozzle mouthpiece 3, for example a nozzle tip. The latter forms an end (unspecified) nozzle outlet opening, which opens via a (also not visible) sprue in the mold insert of the injection mold. At its opposite end, the material pipe 2 carries a flange 4, which bears sealingly against a distributor (not shown) of the injection mold.

On the outer circumference of the material tube 2, a (only schematically illustrated) electrical heating element 20 is placed. This has a tubular or sleeve-shaped carrier element and a thick-film heating applied thereto. The latter is essentially formed by a ceramic insulating layer applied directly to the carrier element and a heating layer applied above it, wherein the heating layer has a meander-shaped heating conductor track, which is provided with connecting surfaces 21 at its ends. An outer cover protects and insulates the heating conductors. The arbitrarily configurable Heizleiterbahnen can be applied depending on the required power in different density and arrangement on the insulation layer. As a result, a defined temperature distribution within the material pipe 2 can be achieved if required. The structure of such a heating element is in DE 10 2006 049 667 A1 described, the contents of which are hereby incorporated by reference. An alternative heating element is in DE 10 2006 049 669 A1 , the contents of which are also incorporated by reference.

On the connection surfaces 21 of the heating conductor connection contacts 22, 23 are applied, for example in the form of connecting wires or lines, which are secured by means of electrically conductive adhesive layers on the Heizleiterbahnen. The construction of such an electrical connection with a plurality of electrically conductive adhesive layers is in DE 10 2008 015 376 A1 described, the contents of which are hereby incorporated by reference. However, the connection contacts 22, 23 can also be attached to the connection surfaces 21 by other methods, for example by welding or by mechanical means.

The material pipe 2 is seated together with the heating element 20 in a housing 5 which is inserted into a suitable recess in the tool and the nozzle 1 centered with respect to the gate. In the housing 5 is - as in Fig. 3 to see - a lateral Recess 7 introduced, which is open in the longitudinal direction L of the nozzle 1 to the manifold or the flange 4 of the material tube 2 out. The recess 7 serves to receive and carry out a connection device 10, which is arranged on the heating element 20, in particular over the connection surfaces 21 of the heating element 20 and projects radially outward. One recognizes in Fig. 3 in that, in the assembled state of the nozzle 1, the flange 4 of the material pipe 2 rests on the end 6 of the housing 5 and thereby closes the recess 7 towards the distributor.

The connection device 10 serves to generate an electrical connection between the electrical heating element 20 and a connecting line 30, wherein the connection contacts 22, 23 of the heating element 20 are brought into contact with contact elements 32, 33 of the connecting line 30. The latter is connected to a (not shown) power source, which supplies the heating element 20 during operation of the hot runner nozzle 1 with electricity.

The connection device 10 has a substantially bell-shaped or hat-shaped insulating body 50, which is preferably made of a ceramic material or of another insulating material. It has a neck portion 52 and a base portion 54 and receives the terminal contacts 22, 23 of the heating element 20, wherein it electrically separates from each other. In the mounted position, the insulating body 50 sits - as Fig. 1 and 2 show - with its neck portion 52 in a receiving sleeve 70 which is enclosed by an outer sleeve 90. The latter is connected to the housing 5 in order to fix the connection device 10, in particular the insulating body 50 and the receiving sleeve 70, to the heating element 20 or to the hot runner nozzle 1.

Like the enlarged view of Fig. 2 shows in more detail, the connection contacts 22, 23 of the heating element 20 end with contact pins 24, 25 are provided. These are preferably made of silver or another noble metal and firmly connected by soldering or crimping (crimping) with the connection contacts 22, 23 of the heating element 20.

Each contact pin 24, 25 is non-positively and / or positively inserted from below into the insulating body 50, which is provided for this purpose with two parallel receiving channels 51. Both channels 51 each terminate in a separate cavity 53, which are formed in the region of the base portion 54 (see Fig. 5 and 7 ).

One recognizes in Fig. 2 in that the cavities 53 are dimensioned such that they can receive the connection contacts 22, 23 and that the base section covers both the connection contacts 22, 23 and the connection surfaces 21 of the heating conductor paths. In this way, the relatively sensitive areas of the electrical connections are protected to the outside.

The contact pins 24, 25 may be formed and inserted into the insulating body 50 that they - Fig. 2 shown - with their free ends do not protrude beyond the end face of the neck portion 52 of the insulator 50. However, in an alternative embodiment, you may well protrude beyond the end face of the neck portion 52 as shown in FIG Fig. 3 is shown. In this case, the contact pins 24, 25 provided with (unspecified) tips.

As Fig. 3 and 4 show, in the insulating body 50, a further contact pin 26 is provided for a ground connection. For this purpose, a further receiving channel 55 is formed within the insulating body 50 (see also 6 and 7 ), which receives the further contact pin 26 non-positively and / or positively. The further receiving channel 55 terminates in a lateral recess 56. This serves to carry out a (not shown) lead wire or a line to connect the further contact pin 26 with the carrier element of the heating element 20.

The further contact pin 26 is also made of silver or other precious metal and connected by soldering or crimping (crimping) with the connection wire for the ground connection to the heating element 20. He can - as in Fig. 4 indicated already be preassembled in the insulating body 50 in order to simplify the assembly of the connection device 10.

Thus, when connecting the electrical heating element 20 to the connecting line 30 and to the power always the ground terminal or ground contact is first made, the further contact pin 26 is formed longer than the contact pins 24, 25th

The in the Fig. 9 to 12 shown receiving sleeve 70 has a cylinder jacket 71 which is supported with its lower edge 73 on the base portion 54 of the insulating body 50. It has distributed over the circumference a plurality of extending in the axial direction A slots 79, which divided the cylinder jacket 71 into resilient portions 711. At its upper edge 75, a flange edge 78 is formed on the receiving sleeve 70, which protrudes radially outward relative to the cylinder jacket 71.

Within the receiving sleeve 70, the cylinder jacket 71 forms an inner flange edge 77 in the lower region. This defines a through opening 771 for the neck section 52 of the insulating body 50, the inner diameter of the through opening 771 being slightly larger than the outer diameter of the neck section 52.

On the inner periphery of the through hole 771, a recess 772 is formed for a projection 522, which is formed laterally on the neck portion 52 of the insulating body 50 in the longitudinal direction A. When the insulating body 50 and the receiving sleeve 70 are mounted, the projection 522 sits essentially in a form-fitting manner in the recess 772, so that the two together form an anti-rotation device 60. Over the inner flange edge 77, two guide grooves 74 are provided in the cylinder jacket 71 in the axial direction A, which are parallel to each other. Approximately halfway up the guide grooves 74, a circumferential latching groove 72 is further introduced into the cylinder jacket 71, which forms a (not designated) latching edge towards the upper edge 75 of the receiving sleeve 70.

Below the inner flange edge 77, a spring element 76 is arranged between the receiving sleeve 70 and the insulating body 50, which is preferably formed integrally with the receiving sleeve 70. The spring element 76 exerts after installation of the connection device 10 a slight pressure on the insulator 50, so that it always sits reliably on the heating element 20, without damaging this.

At the lower end of the receiving sleeve 70, a tab 80 is formed laterally. This is dimensioned and designed such that after mounting of insulator 50 and receiving sleeve 70, the recess 7 formed in the housing 5 is closed by the tab 80. In this case, the tab 80 and the housing 5 are substantially flush with one another.

In the tab 80, a recess 82 is introduced. This is used to perform a connection line 100 for a (not shown) temperature sensor that detects the temperature generated by the heater 20 and the power supply or forwards an external control. In the connecting line 100, a plug 110 is formed in order to disconnect the temperature sensor when removing the nozzle 1 or when replacing the heating element 20 from the power supply or the control can. The Fig. 13 and 14 show the outer sleeve 90, with both the insulating body 50 and the receiving sleeve 70 are fixed to the hot runner nozzle 1. The outer sleeve 90 has a cylinder jacket 93, the inner diameter of which substantially corresponds to the outer diameter of the cylinder jacket 71 of the receiving sleeve 70. At the upper end 91 of the cylinder jacket 93, a circumferential groove 92 is formed inside. This serves to receive the radially outwardly projecting flange edge 78 of the receiving sleeve 70. At its lower end 94, a thread 95 is formed on the outer circumference of the cylinder jacket 93. This engages in a corresponding internal thread 8 in the housing 5 of the hot runner nozzle 1, wherein the internal thread 8 is formed in the recess 7 of the housing 5.

To produce an always reliable and detachable electrical contact between the terminal contacts 22, 23 or the contact pins 24, 25 of the heating element 20 and the contact elements 32, 33 of the connecting line 30 and between the further contact pin 26 and the ground terminal in the connecting line 30, is the end on the connecting line 30, a three-pole plug 36 is formed. This has on its outer circumference radially outwardly projecting locking elements 38 which engage in the insertion of the plug 36 into the receiving sleeve 70 in the locking groove 72. So that the plug 36 can not be inserted the wrong way round, two (not shown) projections are formed on the outer circumference, which engage like a key in the guide grooves 74 of the receiving sleeve 70. The plug 36 can not be inserted the wrong way around in the receiving sleeve 70.

The plug 36 is dimensioned and designed so that after the locking of the locking elements 38 behind the locking edge of the locking groove 72, the contact elements 32, 33 of the connecting line 30, the contact pins 24, 25 of the heating element 20 always reliably electrically contact.

For the installation of the connection device 10, the connection contacts 22, 23 of the heating element 20 are initially provided with contact pins 24, 25. These are then inserted into the insulating body 50, wherein the contact pins 24, 25 in the Recording channels 51 are locked or jammed. The pre-assembled in the insulating body 50 pin 26 for the ground terminal is connected with its (not shown) line to the support element of the heating element 20, preferably by soldering or mechanically. Thereafter, the insulating body 50 is placed with its base portion 54 on the heating element 20, wherein the base portion 54, the connection surfaces 21 and the connection contacts 22, 23 of the heating element 20 covers. The neck portion 52 of the insulating body 50 is approximately at right angles and radially from the surface of the heating element 20 from.

After placing the insulating body 50 on the heating element 20, the material tube 2 is inserted into the housing 5 of the hot runner nozzle 1 until the flange 4 is seated on the front end on the rear end 6 of the housing 5. In this case, the radially outwardly projecting insulating body is inserted into the recess 7 in the housing 5.

Subsequently, the receiving sleeve 70 and the outer sleeve 90 are placed on the neck portion 52 of the insulating body 50, wherein the sleeves 70, 90 have been previously inserted into each other by e.g. the outer sleeve 90 is fitted from above onto the receiving sleeve 70. The sections 711 of the cylinder jacket 71 are pressed inwardly by the upper flange edge 78. Once the receiving sleeve 70 has reached its end position in the outer sleeve 90, the flange edge 78 passes into the locking groove 92 of the outer sleeve 90 and the sections 711 can spring outwards again. It can be seen that the receiving sleeve 70 and the outer sleeve 90 are arranged concentrically to each other and that the receiving sleeve 70 is axially fixed-rotatably mounted in the outer sleeve 90.

Once the external thread 95 of the outer sleeve 90 and the internal thread 8 engage in the recess 7 of the housing 5, the outer sleeve 90 can be screwed by simply turning with the housing 5. The receiving sleeve 70 is already seated over the neck portion 52 of the insulating body, wherein the anti-rotation device 60 ensures that the receiving sleeve 70 does not rotate. This lowers rather on the insulating body 50 from until the spring elements 76 rest on the base portion 54 and the tab 80, the recess 7 in the housing 5 closes. The spring elements 76 press the insulating body 50 with slight force against the heating element 20th

To connect the heating element 20 to the power supply only the plug 36 must be inserted into the receiving sleeve 70. Initially, the leading pin 26 establishes the ground connection. As soon as the plug 36 is completely inserted into the receiving sleeve 70, the latching elements 38 lock in the latching groove 72, so that the plug connection can no longer come loose. The contact pins 24, 25 contact the contact elements 32, 33 of the connection line 30. As soon as the temperature sensor is connected, the hot runner nozzle 1 can be operated.

To release the electrical contact, only the plug 36 has to be pulled out of the receiving sleeve 70. Here, the locking elements 38 are retracted by either a corresponding actuator is actuated or the plug is equipped with a so-called push-pull technique, as is known for example from the company LEMO.

In another embodiment of the invention, the receiving sleeve 70 and the tab 80 are formed separately (see Fig. 15 ). The tab 80 carries this laterally a ring 84 which is placed from below on the lower edge 73 of the receiving sleeve 70. For this purpose, the edge 73 is preferably of stepped design and provided with a circumferential recess (not specified) into which a nose 85 formed in the ring 84 engages for preventing rotation and positioning aid.

The invention is not limited to one of the above-described embodiments, but can be modified in many ways. Thus, the insulating body 50 may in principle also have a different shape, for example cylindrical with a narrow radial flange, as an approach for the sleeves 70, 90. If no ground connection is used or needed for the electrical connection, the plug 36 may also be formed bipolar ,

It can be seen that the invention relates to a connection device 10 for producing an electrical connection between an electrical heating element 20 of a hot runner nozzle 1 and a connecting line 30, which is connected to a power source, wherein the connecting line 30 contact elements 32, 33 which are connected to terminal contacts 22, 23 of the heating element 20 are electrically contacted. The connection contacts 22, 23 of the heating element 20 terminate in an insulating body 50, which electrically disconnects the connection contacts 22, 23 from each other, the latter end with contact pins 24, 25 are provided. Another contact pin 26 in the insulating body 50 serves as a ground terminal. For fixing the insulating body 50 on the heating element 20 or on the hot runner nozzle 1, a receiving sleeve 70 and a concentrically arranged outer sleeve 90 are provided. In this case, the insulating body 50 is at least partially arranged in the receiving sleeve 70, while the outer sleeve 90 is screwed in the manner of a union nut with the housing 5 of the hot runner nozzle 1. The outer sleeve 90 is to axially fixed-rotatably mounted on the receiving sleeve 70. The latter forms a socket for a plug 36, which is formed at the end of the connecting line 30, and the contact elements 32, 33 and possibly another contact for the further contact pin 26 integrated. The plug 36 can be fixed in or on the receiving sleeve 70 in such a way that the contact elements 32, 33 of the connecting lead 30 contact the connecting contacts 22, 23 of the heating element 20 and the ground contact electrically contacts the further contact pin 26.

All of the claims, the description and the drawings resulting features and advantages, including design details, spatial arrangements and method steps may be essential to the invention both in itself and in various combinations.

LIST OF REFERENCE NUMBERS

A

axially

L

longitudinal direction

1

hot runner nozzle

2

material tube

3

Nozzle mouthpiece

4

flange

5

casing

6

The End

7

recess

8th

inner thread

10

connecting device

20

heating element

21

terminal area

22

connection contact

23

connection contact

24

pin

25

pin

26

another contact pin

30

connecting cable

32

contact element

33

contact element

36

plug

38

locking element

50

insulator

51

receiving channel

52

neck section

522

head Start

53

cavity

54

base section

55

receiving channel

56

recess

60

twist

70

receiving sleeve

71

cylinder surface

711

section

72

locking groove

73

lower edge

74

guide

75

upper edge

76

spring element

77

flange

772

recess

78

flange

79

slot

80

flap

82

recess

84

ring

90

outer sleeve

91

top end

92

circumferential groove

93

cylinder surface

94

lower end

95

thread

100

connecting cable

Claims (17)

Connecting device (10) for producing an electrical connection between an electrical heating element (20) of a hot runner nozzle (1) and a connecting line (30) which is connected to a power source, wherein the connecting line (30) contact elements (32, 33), the with connection contacts (22, 23) of the heating element (20) are electrically contacted,
characterized, That the connection contacts (22, 23) of the heating element (20) terminate in an insulating body (50) which electrically separates the connection contacts (22, 23) from one another, ■ that the insulating body (50) is arranged at least in sections in a receiving sleeve (70), and ■ that the connecting line (30) in such or on the receiving sleeve (70) can be fixed, that the contact elements (32, 33) of the connecting line (30) electrically contact the terminal contacts (22, 23) of the heating element (20). Connection device according to claim 1, characterized in that the connection contacts (22, 23) of the heating element (20) end with contact pins (24, 25) are provided. Connecting device according to claim 1 or 2, characterized in that the insulating body (50) has a neck portion (52) and a base portion (54). Connecting device according to claim 3, characterized in that the receiving sleeve (70) on the base portion (54) of the insulating body (50) is supported. Connecting device according to claim 3 or 4, characterized in that the base portion (54) of the insulating body (50) covers the connection contacts (22, 23) of the heating element (20). Connecting device according to one of claims 1 to 5, characterized in that in the insulating body (50), a further contact pin (26) is provided. Connection device according to claim 6, characterized in that the further contact pin (26) is designed to be longer than the contact pins (24, 25). Connecting device according to claim 6 or 7, characterized in that the further contact pin (26) forms a ground connection for the heating element (20). Connecting device according to one of claims 1 to 8, characterized in that between the Isolierköper (50) and the receiving sleeve (70) an anti-rotation device (60) is formed. Connecting device according to one of claims 1 to 9, characterized in that the connecting line (30) end a plug (36) which is releasably in the receiving sleeve (70) can be fixed. Connecting device according to one of claims 1 to 10, characterized in that between the receiving sleeve (70) and the insulating body (50), a spring element (76) is arranged. Connecting device according to one of claims 1 to 11, characterized in that the receiving sleeve (70) carries at its lower end a tab (80). Connecting device according to claim 12, characterized in that the tab (80) is provided with a recess (82) for passing a connecting line (100) for a temperature sensor. Connecting device according to one of claims 1 to 13, characterized in that the receiving sleeve (70) is arranged concentrically in an outer sleeve (90). Connecting device according to claim 14, characterized in that the receiving sleeve (70) is axially fixed-rotatably mounted in the outer sleeve (90). Connecting device according to claim 14 or 15, characterized in that the outer sleeve (90) with its lower end (94) on a housing (5) of the hot runner nozzle (1) can be fixed. Hot runner nozzle (1) for an injection mold, with a connection device (10) according to one of claims 1 to 16.

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